Numerous attempts have been made to suppress epileptic seizures in human patients with indirect electrical stimulation at sites remote from the epileptic focus, including cerebellum (Cooper et al., 1976; Van Buren et al., 1978), thalamus (Cooper et al., 1985; Fisher et al., 1992), and vagal nerve (Murphy et al., 1995; McLachlin, 1997). Surprisingly, there has been far less investigation of the technology required to directly control an epileptic focus electrically. It has been shown that direct current injection into tissue could suppress evoked (Kayyali and Durand, 1991) or spontaneous (Nakagawa and Durand, 1991; Warren and Durand, 1998) epileptiform activity in brain slices. Even simple periodic pacing of a neuronal network with direct electrical stimulation (Kerger and Schiff, 1995) can reduce seizure-like events. In addition, there is some evidence that nonlinear control schemes might be useful in manipulating epileptiform activity (Schiff et al., 1994). In each of these cases, the stimulation was applied in the form of short current pulses directly into the tissue that evoke neuronal firing. Recently, it was demonstrated that steady state (DC) electric fields oriented parallel to pyramidal cells were capable of suppressing epileptic seizure activity in in vitro hippocampal brain slices (Gluckman et al., 1996a). Such field application led to nearly complete suppression of neuronal activity, yet due to a combination of polarization effects (electrode and tissue) and neuronal adaptation, this effect was transient.